Ironing apparatus



July 26, 1960 J. ROTHENBERGER IRONING APPARATUS Filed March 26, 1957 Fig.)

' INVENTOR. J0me farrrz/vamqik WWM' United States Patent O 2,946,147 IRONING APPARATUS Jakob Rothenberger, 49 Kronleinstr'asse,

Zurich, Switzerland Filed Mar. 26, 1951, sets... 648,676 Claims priority, application Switzerland Mar. 27, 1956 2 Claims. (Cl. ss-z This invention relates to an apparatus for continuously ironing clothes and more particularly to a combination of a chamber for drying the clothes in order to increase production'prior to feeding the clothes to a pressing device.

An object of this invention is to provide an apparatus for continuously ironing clothes and wherein further drying of clothes after pressing is unnecessary and results in an increase in the output of pressed clothes.

Practically, the invention permits reducing the processing time required for pressing clothes by. pre-drying clothes. With conventional apparatus the pressing unit performs the major part of the drying of the clothes. The processing time required Was therefore comparatively long and the rate of transit of the clothes low unless a large and correspondingly more costly pressing unit was employed. However, a thorough investigation of the drying and pressing process revealed that the contact'pressure exerted on the clothes is of little importance in the practice of drying, as shown in the diagram in Fig. l of the drawing. 7

The abscissa of the diagram represents the period of treatment t? and the ordinate the moisture content F in percent of the dry weight of a plain cloth having a weight of 270 g./m. The drying temperature is assumed to be 150 C.

Curve A shows the decrease in the moisture content on application of a contact pressure of 200 g./cm. to a residual moisture of approx. 10 percent after a processing time of 12 seconds. This contact pressure corresponds to that of the trough mangles employed; it is operative over a relatively limited circumferential area owing to the compressibility of the roller coating. I Curve B shows the decrease in the moisture content on application of a contact pressure of only 60 g./cm. the other conditions remaining the same. As the differential length (1" of ordinate T shows, the residual moisture content after a 12-second processing period is a maximum of 7 percent higher than in curve A, which result can be confirmed by appropriate tests whenever desired. The diagram may also be interpreted to the effect that the required processing time in curve B is only 2 seconds longer than in curve A if the same residual moisture of 10 percent is to be obtained. This means that the contact pressure contributes very little to the drying action. The drying time t required approaches an indistinguishable minimum value at contact pressures larger than 500 gms./cm. the other conditions being the same. Contact pressure may accordingly be dispensed with for drying; the only requirement being that the full surface of the cloth to be dried establishes intimate contact with the heating surface. For economical ironing of clothes pressure need be applied only in the pressing and the pressing path need not extend more than 15 percent of the entire drying path.

The concept of the present invention is based on em- 2,946,147 .Patented July 26, 1960 2 ploying a drying unit provided at the inlet side of the pressing apparatus. The drying unit removes over 50 percent of the moisture from the material to be dried. This will not only protect the clothes but enable a substantial reduction in the cost of the ironing apparatus.

The invention further relates to an apparatus having a drying unit provided at the inlet side of the pressing device which unit is provided with at least one heated drying member having a smooth and heated surface, and conveyer means enabling the clothes to be continuously passed over this surface in sliding contact, the dimension in the direction of feed and the heating capacity being so designed that over 50 percent of the moisture content is removed from the clothes during their passage.

Fig. 1 shows a diagram wherein the abscissa represents the period of treatment and the ordinate the moisture content.

Figs. 2 and 3 show diagrammatic longitudinal sections of two embodiments of the ironing apparatus according to this invention.

The apparatus illustrated in Fig. 2 includes a pressing device having a cylinder 1 and a trough 2, and a drying unit arranged at the inlet side of the pressing device. The drying unit comprises substantially a steam-heated drying chamber 3 and an endless belt conveyer 4 passing through the member 3, which conveyor is entrained around a driving roller 5, an adjustable tension roller 6 and guide rollers 7 to 10.

The drying chamber 3 is equipped with a heat insulating casing 11 and a system 12 of steel tubes arranged therein for the purpose of conducting the heating steam. The system 12 is covered by a sheet steel jacket 13. steam inlet and a steam outlet are shown at 14 and 15 respectively; several may be provided and the heating tubes may be interconnected in groups. In order to reduce friction, the jacket 13 is mirror-finished and forms an effective heating surface along which the clothes are passed in sliding contact by the conveyer 4. In order to ensure perfect and uniform contact under tension over the entire heating surface 13, the chamber is curved and convoluted in several sections as shown in Figure 2. The

plain clothes are placed on the conveyer 4 at P and smoothed on the support 16. The conveyer 4 also serves as a feed member and is held taut by the roller 10 of which the axle ends are subject to pressure by springs 17. Rollers 8 and 10 are provided with a resilient coating to allow for clothes of various thicknesses so that no stoppages will occur in the passage thereof. The clothes pass the drying unit in several loops (Fig. 2 shows two such loops only for the sake of clarity), and are automatically inserted in the pressing device 1, 2, which they leave again at P in finished condition.

The reverse surface of the clothes which contact surface 13- engage the surface of trough 2.

There is immediate continuous removal of the steam generated in drying the clothes from the interior of drying chamber 3, preferably effected by a suction device including a withdrawal tube 18 and independent of the heating steam system, which suction device may be connected with a blower. constructed of wire cloth. Several spring-loaded perforated guiding or pressure plates 19 may be provided for the conveyer band.

The drying unit may be heated by a heating liquid or by electricity instead of by hot steam. However, steam heating is more economical.

In order to distribute the drying heat evenly through-. out the entirety of the drying unit, the hollow space 20 between the tubes 12 and the sheet-steel casing 13 may be filled with oil or another equalizing liquid. The tension In this case, the conveyor 4 is roller 6 may be equipped with an automatic device for relaxing the conveyer 4 when not in operation.

In the embodiment according to Fig. 3, the heating member is formed from steel sheet 21 bent to a shape lenticular in longitudinal section. The two end edges of this sheet are welded together at 22. The interior of the heating member thus formed is equipped with steam heating tubes 23 which are attached to the two side walls 24 each also formed of steel sheet. The steam heating tubes 23 are surrounded by a heat equalizing liquid, preferably oil, which transmits the heat to the sheet-steel casing 21. The conveyer 25, is passed over a driving roller 26, a tension roller 27 and guide rollers 28 and is preferably perforated. The conveyor 25 is conducted around the heating member so that the heating member has practically its entire outer surface contacted by the clothes. The heating member may also be provided with additional electric immersion heating elements which project into the equalizing liquid.

The heating member and its conveying members 25 to 28 are designed as a self-contained unit in the shape of an upright assembly provided with feet 29 so that it may be stood wherever desired. Baffles 30 and 31 are preferably arranged at the inlet and delivery points for the clothes. These baffies are so designed that two upright heating members may be coupled by being placed beside one another or pushed together so that the clothes will positively be inserted in the next following unit after leaving the first unit while the conveying members are in operation. Thanks to this design, such drying units may be connected in series by standing one beside the other in front of the pressing device. The latter may be a conventional device, the only requirement being that the delivery members of the last drying unit correspond to the feed members of the pressing device.

A suction device for the removal of the steam generated may be provided for each drying unit. It may preferably employ a hot-air inlet line 32 and a suction line 33 with a blower associated therewith, the conveyer 25 being designed as a wire mesh and the entire drying unit being largely closed to the outside by a sheet-metal housing 34. If the drying unit is permanently connected with a pressing device, the outlet line 32 may be connected with the heating unit or the hot-air chamber of the pressing device.

This arrangement of the drying unit possesses the advantage that the entire heating surface is contacted by the clothes and practically enclosed by the latter so that no heat insulation towards the outside is required. The vertical design of the drying unit saves space and enables several units to be connected in a row by simply standing the units behind one another without particular coupling means.

The number of the required drying units is largely determined by the output of the pressing unit, which in turn depends on its cylinder diameter.

The drying device can be so dimensioned that it removes 50-80 percent of the initial moisture content by suction so that the following short pressing zone P (Fig. 1), in which contact pressure is applied, is required to handle very little residual moisture. For this reason, the pressing device which is the most costly part of the apparatus, may be very small, which contributes to the protection of the clothes without impairing the quality of the treatment. As the length of travel through the drying unit may be increased by additional loops or units connected in series, the rate of transit may be substantially increased with a predetermined period of treatment depending on the type of clothes, although a pressing device of small dimensions is being employed.

The apparatus for removing over 50 percent of the moisture content from the clothes by adequately dimensioning the drying unit before the clothes enter the pressing device, therefore enables the output of the apparatus to be substantially increased, while the quality of the treat- Pressing device cylinder diameter: Transit rate 30 cm. m /min 8,3 35 cm. m./min. 8.6 cm. m./min. 9.0 60 cm. m /min. 10.3

When two drying units are employed:

Pressing device cylinder diameter: Transit rate 30 cm. m./min... 14.6 35 cm. m./min. 15.0 40 cm m./min. 15.3 60 cm. m./min. 16.6

These figures show that the use of a larger pressing device which is known to involve extreme costs, causes the transit rate to increase but very slightly, while the use of a second drying unit, which is far less expensive, enables the rate to be increased very substantially. (These figures do not consider the 5-10 percent higher production owing to the contact pressure in the pressing device.)

Both embodiments of the drying units enable additional electrical immersion heaters acting upon the equalizing liquid to be provided with ease. This will further increase the output since experience shows that the drying temperature exercises a substantial influence on the treatment period required. By way of example, drying times for various drying temperatures employed, with the other conditions remaining unchanged and a constant degree of dryness obtained, are:

Various changes and modifications may be made without departingfrom the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

1. An apparatus for continuously drying clothes, comprising a drying chamber having an outer surface, heating means including a heating fluid in said drying chamber for heating said outer surface, said heating means further including a network of tubes in intimate contact with said heating fluid within said drying chamber, means for delivering steam to said tubes to heat said heating fluid, endless perforated belt conveyor means disposed adjacent said drying chamber and having a portion conforming to and disposed immediately adjacent said outer surface, and means for driving said conveyor means connected thereto, said drying chamber having a plurality of curved sections, each of said sections having a mirror-finished metal hous ing thereabout, said portion of said conveyor means including loops extending between said curved sections and being resiliently urged taut between said curved sections.

2. An apparatus for continuously drying and ironing clothes, comprising a drying chamber having a mirrorfinished outer surface, heating means including a heating fluid in said drying chamber for heating said outer surface, said heating means further including a network of tubes in intimate contact with said heating fluid within said drying chamber, means for delivering steam to said tubes to heat said heating fluid, endless perforated conveyor means disposed adjacent said drying chamber and having a portion conforming to and disposed immediately adjacent said outer surface, means for driving said conveyor means, a pressing device disposed immediately adjacent said conveyor means, said pressing device including a cylinder and a trough, said conveyor means feeding clothes onto said cylinder with the opposite side of the clothes which engage said outer surface engaging said trough, said drying chamber having a plurality of curved sections, said portion of said conveyor means including References Cited in the file of this patent loops extending between said curved sections, means 5 2,054 512 resiliently urging said loops taut between said curved sections, and a withdrawal-tube carried by said drying chamher and extending between said curved sections to withdraw steam from said network of tubes and between said sections.

UNITED STATES PATENTS Wendell Apr. 24, 1894 Wilson et a1 Dec. 15, 1936 Zigler June 11, 1940 Manley May 8, 1945 Sando Feb. 26, 1946 Taylor .a... Jan. 6, 1953 

